The rishis headed by Shaunaka were in Naimisharanya, engaged in a yagna being done for 12 years. At one time, Ugrashrava, the son of Lomaharshana, called Sauti, who is very well versed with the Puranas, to visit them.
After their yagna, offerings for the day was over, the rishis offered him a seat and requested him to tell them the sacred stories from the Mahabharata. He began the description of Mahabharata likening it to a tree. The seed is the first chapter which contains the contents of the entire Mahabharata. The ‘Pauloma’ and ‘Astika’ chapters of the Mahabharata are the roots. The ‘Sambhava Parva’ that describes the beginnings is the trunk.
The ‘Sabha’ and ‘Aranya Parva’ are like the perches on which birds alight. The chapter on Drona is like the leaves of the tree and that on Karna are the flowers. In the ‘Shalya Parva’, the fragrances of the Mahabharata begin to waft. The ‘Stri’ and ‘Aishika Parva’ chapters talk about finding cool shades of the tree. The ‘Shanti Parva’ is the fruit of the tree, containing the essence of the Mahabharata.
The key characters of the Mahabharata—the Pandavas and the Kauravas—are also compared to two trees. The tree of anger is Duryodhana. He is a big tree whose very form is anger and hatred. The trunk of that tree is Karna, and Shakuni forms the branches of that tree. Dushasana is none other than the fruits and flowers of that tree and the very root of that tree is the King Dhritarashtra, who is an Amanishi—the one who cannot think properly using his intellect.
There is another tree called Yudhishtira. The nature of that tree is dharma or existence. The trunk of that tree is Arjuna and Bhima Sena manifests himself as the branches of that tree. Nakula and Sahadeva–the sons of Madri by Pandu are the fruits and flowers of the tree. The root of the tree is none other than Sri Krishna, Brahma or God and the knowers of that Brahma.
King Pandu conquered many countries, and retired to a forest and lived amidst the rishis. There his love for hunting made him do something that he would repent for later.
He killed a stag that was in a loving embrace with his mate. As a result of this, Pandu was cursed that he would die if he touched any other woman for pleasure. His two wives, Kunti and Madri, prayed to the gods Dharma Devata for Yudhishtira, Vayu for Bheema, Indra for Arjuna and the Ashwini Devatas for Nakula and Sahadeva.
The people welcomed the brothers with joy. The Pandavas grew there in the forest studying the books of knowledge and all the shastras.
(www.sharanyachaitanya.blogspot.in)